The reaction of isobutane with low (C.sub.2 -C.sub.5) molecular weight olefins to produce C.sub.6 -C.sub.9 paraffins is commonly referred to as alkylation. In commercial practice this reaction is carried out in the presence of acid type catalysts such as concentrated sulfuric acid or HF. The reaction is an important process to the petroleum industry as it upgrades chemical compounds in crude oil for which there may be little value to high octane fuel components. The two acids mentioned above are the catalysts of choice as the process is now practiced commercially, but each of them while producing a satisfactory alkylate for fuel blending has serious drawbacks. The use of HF presents a significant ecological hazard should it escape into the atmosphere, and the sulfuric acid process is very corrosive and energy consuming as it needs to be operated at below ambient temperatures in order to provide a satisfactory alkylate. Certain solid compositions with acidic properties have been found to catalyze this reaction as subsequently disclosed.